Aidan O'Brien has been warned by the British Horseracing Authority that a repeat of his failure to allow vets fully to examine one of his horses earlier this year would lead to him being banned from having runners in Britain.

The champion Irish trainer was fined a total of £10,400 for his conduct in the aftermath of York's Dante Stakes on 13 May after he refused to allow his travelling head groom, Pat Keating, to trot the race's winner Cape Blanco in front of the BHA vets after the race.

Although an original charge of bringing racing into disrepute was reworded to a lesser offence of "acting in a manner prejudicial to the proper conduct of horseracing"‚ the BHA's disciplinary panel issued a sternly worded statement, highly critical of O'Brien, despite his admission of guilt.

"There was little else about this episode which has reflected well upon him," the statement said. The published findings of the panel reveal that the vets Lynn Hillyer and Mark Collins were allowed to examine Cape Blanco in the immediate aftermath of his victory, where they assessed him as being "five-tenths lame at the trot".

But when the vets returned to inspect the colt after the last race and pass him fit for the return journey to O'Brien's Tipperary stables, and finding his condition seemed to have improved and that he was only "one-tenth lame at the walk", Keating, acting on the instructions of O'Brien, refused to allow them to trot the horse.

Keating, who left the racecourse with the horse without attending a stewards' inquiry called into the incident, was not given a penalty by the BHA panel, who accepted his "difficult position". However, O'Brien was fined £1,400 for failing to obey the stewards and instructing Keating not to attend the inquiry, and a further £9,000 for his refusal to allow the vets to complete their examination.

Describing the offences as "a very serious matter", the panel's statement said that they had "considered very carefully whether the proper approach on this occasion would be to deal with the issue by imposing a period of time during which horses entered in races in Great Britain by Aidan O'Brien would not be allowed to race", and also warned that a breach of the Rules in similar circumstances would lead to restrictions being placed on his runners.